STRESS COUPLED TRANSPORT IN POLYMER FIBERS AND RIBBONS.

The permeation of organic solvents in commercial polymers has often been reported to have drastic effects on the structural integrity of these materials. In cases where coupled effects of stress and diffusion exist, the material property modifications that take place due to sorption under stress may not be the same as those predicted on the basis of 'conventional' stress-free diffusion experiments. A technique has been developed, in our laboratory, to measure the linear mass density of fibers and ribbons, and adapted to the study of stress/strain coupled diffusion in polymeric materials. Preliminary data aquired from the apparatus is in reasonable quantitative and qualitative agreement with the closest available information in the literature. This method can now be employed to study diffusion characteristics, stress/strain effects, modulus variations during diffusion, the drying process, solvent evaporation and mass gain or loss during heat treatment of polymers.